Faculty of Natural Sciences and Mathematics

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Minerals from Macedonia. XXX. Complementary use of vibrational spectroscopy and X-ray powder diffraction for spectra-structural study of some cyclo-, phyllo- and tectosilicate minerals. A review
(Society of Chemists and Technologists of Macedonia, 2016-12-27)
Jovanovski, Gligor
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<jats:p>A review of the results of the complementary use of vibrational spectroscopy (infrared and Raman) and X-ray powder diffraction in the process of identification and spectra–structure correlation of some cyclo-, phyllo- and tectosilicate minerals originating from the Republic of Macedonia is presented. The following minerals are studied: schorl, Na(Fe2+,Mg)3Al6(BO3)3Si6O18(OH)4; beryl, (Be,Mg)3Al2Si6O18; chrysotile, Mg3Si2O5(OH)4; antigorite, (Mg,Fe2+)3Si2O5(OH)4; talc, (Mg,Fe2+)3Si4O10(OH)2; clinochlore, (Mg,Fe2+)5Si3(Al,Cr)2O10(OH)8; cymrite, BaAl2Si2O8×H2O; montmorillonite, (K,Ca)0.3(Al,Mg)2Si4O10(OH)2×nH2O; muscovite, KAl2(Si3Al)O10(OH,F)2; phlogopite, KMg3(Si3Al)O10(OH,F)2; biotite, K(Mg,Fe2+)3AlSi3O10(OH,F)2; sheridanite, (Mg,Al)6(Si,Al)4O10(OH)8; albite, NaAlSi3O8; microcline, KAlSi3O8; sanidine, (K,Na)(Si,Al)4O8 and stilbite, Na3Ca3Al8Si28O72×30H2O.</jats:p>
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Insights into the infrared and Raman spectra of fresh and lyophilized royal jelly and protein degradation IR spectroscopy study during heating
(Society of Chemists and Technologists of Macedonia, 2015-05-05)
Lazarevska, Sofija
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<jats:p> In terms of chemical composition, a honeybee secretion known as royal jelly (RJ) is very complex product containing water, proteins, carbohydrates, lipids, mineral salts and small amounts of polyphenols, vitamins and enzymes. Despite its chemical diversity, the bands originating from vibrational modes of the present proteins were successfully assigned in 1800–1200 cm–1 (Raman and IR) region where the interference of bands from other vibrational species is not substantial. The protein bands were attributed to amide I, amide II and amide III modes and their intensities, additionally, enabled to determine the protein secondary structures. The remaining bands up to 4000 cm–1 were attributed to other group vibrations whereas the region below 1200 cm–1 comprises bands from complex interacting modes within the major RJ components that can not be unequivocally attributed to distinct modes. The work also represents a pioneering effort to collect and interpret the Raman spectrum of fresh and lyophilized RJ samples and to correlate and describe the observed similarities/differences between IR and Raman spectra.</jats:p>
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Application of k0-method of neutron activation analysis for determination of trace elements in various mineral samples: a review
(Society of Chemists and Technologists of Macedonia, 2015-05-22)
Jacimovic, Radojko
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Stafilov, Trajce
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Stibilj, Vekoslava
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Taseska, Milena
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<jats:p>Various trace elements in different types of arsenic (orpiment, As2S3; realgar, As4S4; lorandite, TlAsS2), antimony (stibnite, Sb2S3), copper (brochantite, Cu4SO4(OH)6; chalcanthite, CuSO4·5H2O; chalcopyrite, CuFeS2; covellite, CuS; native copper, Cu) and iron based geological materials (hematite, Fe2O3; pyrite, FeS2; chalcopyrite, CuFeS2) were determined using k0-method of neutron activation analysis (k0-NAA) in both forms: instrumental (k0-INAA) and radiochemical (k0-RNAA). In order to avoid interferences from the matrix element (As, Sb, Cu and Fe), various procedures were applied for its removal. Elimination of the matrix element enabled investigation from 35 to 47 trace elements in the samples using short (up to few minutes) and long (up to 20 hours) irradiations in typical irradiation channels of TRIGA reactor. The minerals were collected from various localities within the Republic of Macedonia, except covellite, which was obtained from Bor, Serbia.</jats:p>
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Evaluation of immunoconjugates of non-radioactive lutetium- and yttrium-rituximab – a vibrational spectroscopy study
(Society of Chemists and Technologists of Macedonia, 2015-11-12)
Gjorgieva Ackova, Darinka
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Smilkov, Katarina
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Janevik-Ivanovska, Emilija
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Stafilov, Trajče
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Arsova-Sarafinovska, Zorica
<jats:p>Fourier Transform Infrared (FT-IR) and Raman spectroscopy were used to study the molecular structure of the recombinant monoclonal antibody and anti-CD20-conjugates which are intended to be used as anti-cancer therapeutic agents. We characterized the secondary structure of a therapeutic immunoconjugates, formulated with different bifunctional chelating agents and labeled with non-radioactive lutetium and yttrium. The secondary structure content of all three immunoconjugates was assessed to be similar to that of unlabeled antibody. In addition, no significant changes upon lyophilizing procedures were observed. The results demonstrate that amide bands could be taken as analytical peak which enables quick and reliable way for screening of protein pharmaceuticals during development of lyophilized formulations.</jats:p>
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Adsorption of Acetochlor Herbicide on Inorganic- and Organic-Modified Bentonite Monitored by Mid-Infrared Spectroscopy and Batch Adsorption
(Informa UK Limited, 2015-06-04)
Tomić, Zorica P.
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AŠanin, Darko P.
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Đurović-Pejčev, Rada
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ĐorĐević, Aleksandar
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Modification of tin oxide nanoparticles by fluorocarbon solids via a mechanochemical route
(Springer Science and Business Media LLC, 2015-09)
Senna, Mamoru
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Turianicová, Erika
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Zorkovská, Anna
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Kaňuchová, Mária
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The Crystal Structure of Symplesite
(Wiley, 2015-05-27)
Runčevski, Tomče
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Dinnebier, Robert E.
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Jovanovski, Gligor
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Characterization of Nanoscaled TiO2 Produced by Simplified Sol–Gel Method Using Organometallic Precursor
(ASME International, 2015-04-01)
Paunović, Perica
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Češnovar, Andrej
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Gentile, Gennaro
<jats:p>This work is concerned with development of sol–gel method for preparation of nanoscaled TiO2 using organometallic precursor—titanium tetraisopropoxide (TTIP) and determination of the present crystalline phases depending on the temperature of further thermal treatment. The characteristic processes and transformations during the thermal treatment were determined by means of thermal gravimetric analysis and/or differential thermal analysis (TGA/DTA) method. The crystalline structure and size of the TiO2 crystallites were analyzed by means of Raman spectroscopy and X-ray powder diffraction (XRPD) method. At 250 °C, cryptocrystalline structure was detected, where amorphous TiO2 is accompanied with crystalline anatase. The anatase crystallite phase is stable up to 650 °C, whereas at higher temperature rutile transformation begins. It was observed that at 800 °C, almost the whole TiO2 is transformed to rutile phase. According to XRPD analysis, the increase of the temperature influences on the increase of the size of the crystalline particles ranging from 6 nm at 250 °C to less than 100 nm at 800 °C. The size and shape of the TiO2 crystalline particles were observed by transmission electron microscopy (TEM). The shape of the studied samples changes from nanospheres (250, 380, and 550 °C) to nanorods (650 and 800 °C). Morphology of the formed TiO2 aggregates was observed by scanning electron microscopy (SEM).</jats:p>
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Theoretical and experimental study of the vibrational spectra of (para)symplesite and hörnesite
(2015-06-05)
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Stefov, Stefan
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Pejov, Ljupčo
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Jovanovski, Gligor
Arsenate water-bearing minerals, hörnesite (Alšar, Macedonia) and symplesite (Laubach, Germany), were studied by vibrational (IR and Raman) spectroscopy and X-ray powder diffraction. The observed vibrational spectra in both the high (1100-600 cm(-1)) and low (600-450 cm(-1)) wavenumber regions of AsO4 and H2O vibrations could be used to discriminate the two studied minerals. Spectral differences are especially pronounced in the bending and stretching regions of the H2O vibrations in the IR spectra. The observed bands in IR and Raman spectra were tentatively assigned. To support the assignment, IR spectra were theoretically simulated. These calculations were performed using the crystal structure of parasymplesite (no structural information of symplesite has been published so far) and hörnesite using a 3D periodic plane-wave pseudopotential density functional theory approach applying various combinations of exchange-correlation functionals. In this article, we report on the first experimental study of the vibrational spectra of the very rare symplesite mineral.
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Theoretical and experimental study of the vibrational spectra of liroconite, Cu2Al(AsO4)(OH)4∙4H2O and bayldonite, Cu3Pb[O(AsO3OH)2(OH)2]
(Elsevier BV, 2015-07)
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Jovanovski, Stefan
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Pejov, Ljupčo
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Petruševski, Gjorgji
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Ugarković, Sonja

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